The goal of the Data Management and Biostatistics Core is to provide statistical and study design support to achieve the overall goal of PANUC;Understanding basic mechanisms that underiie cognitive impairment in PD. To achieve this goal, the Data Management and Biostatistics Core has the following four specific aims: Aim 1. Enhance research productivity by serving a coordinating role for database development, data cleaning and organization for individual projects. Aim 2. Facilitate conduct of PANUC projects by providing statistical and methodological support, data analysis and interpretation of results. Aim 3. Foster collaborative research by facilitating data sharing across PANUC projects. Aim 4. Facilitate dissemination of study results by assisting in manuscript development and preparation, and in organizing and preparing data for submission to national repositories and databases as required by NIH. RELEVANCE (See Instructions): It is imperative that data management is well organized and that appropriate statistical methods are applied to ensure valid and meaningful results. The Data Management and Biostatistics Core (Core D) will provide this expertise to the Pacific Northwest Udall Center (PANUC), and will play a crucial role in discovering and investigating the mechanisms that underiie cognitive impairment in PD.